Biotransformation of Curcumenol by Mucor polymorphosporus

Terpenoids from the rhizomes of Curcuma kwangsiensis S.G. Lee et C.F. Ling and their anti-inflammatory activities

Three new sesquiterpenes, 4S-1-(3-hydroxybutyl)-7-(11-hydroxypropyl)-10-methyl- cyclohepta-7,5,10-trien-8-one (1), 8R-hydroxy-7-(4S-4,10-dimethyl-5-oxooct-1-en-7-yl)-11- methylfuran-12-one (2), (1S,5R,7S,10R)-1-hydroxy-7-(11-hydroxypropyl)-10-methyl-4- methyleneoctahydronaphthalen-8-one (3), along with 30 known terpenoids (4-33) were obtained from the rhizomes of Curcuma kwangsiensis S.G. Lee et C.F. Ling. Through comprehensive analysis of chemical evidence and spectral data including UV, ECD, IR, 1D and 2D NMR and HR-ESI-MS, as well as quantum chemical calculation, the structures of these novel compounds were successfully determined. Additionally, the inhibitory effects of compounds 1-2, 4-33 on NO production were evaluated in lipopolysaccharide (LPS)-induced RAW264.7 cells. Notably, compound 33 exhibited the most significant inhibitory effect with an IC50 value of 3.55 ± 0.55 μM.

Discovery of potential components characteristic by conjugated enone from the branches and leaves of Croton lauioides with anti-neuroinflammatory activity via regulating the NF-κB pathway

In this study, the chemical composition and pharmacological activity of Croton lauioides were investigated for the first time. The bioactive and HPLC-UV guided isolation led to the discovery of twenty-three conjugated enone-type components (1-23), including nine previously unknown sesquiterpenoid derivatives (1-4, 9-10, 12-14). Notably, compounds 1 and 12 are epoxides containing an endoperoxide bridge (1) or a unique dioxaspiro core (12), respectively. Compounds 2-7 are non-benzenoid aromatics featuring a tropone function, while 9-11 possess a rare rearranged scaffold with tropone shift into benzene. Extensive characterization was performed using NMR spectra, HRESIMS data, and electronic circular dichroism (ECD) calculations. Furthermore, we evaluated the bioactivities of all isolated compounds against neuroinflammation in LPS-stimulated BV-2 microglial cells. Remarkably, most sesquiterpenoid derivatives exhibited significant NO inhibit activities, and compound 5 showed the most potent effect with an IC50 value of 0.14 ± 0.04 μM. Structure-activity relationship (SAR) analysis revealed that sesquiterpenoids modified with endocyclic enone conjugation may serve as a key pharmacophore for NO inhibition, particularly involving aromatic tropone moiety. The qPCR and Western blot results demonstrated that 5 exerted an inhibitory effect on the mRNA levels of iNOS, TNF-α and COX-2 in a time-dependent manner, as well as suppressed the protein expression of iNOS, TNF-α, COX-2. In mechanism, 5 could prevented activation of NF-κB pathway by suppressing phosphorylation of p65 and IκB-α. These findings revealed C. lauioides might be a promising resource for drug candidate development targeting neuroinflammation.

Characterization of Chemical Interactions between Clinical Drugs and the Oral Bacterium, Corynebacterium matruchotii, via Bioactivity-HiTES

In the field of natural product research, the rediscovery of already-known compounds is one of the significant issues hindering new drug development. Recently, an innovative approach called bioactivity-HiTES has been developed to overcome this limitation, and several new bioactive metabolites have been successfully characterized by this method. In this study, we applied bioactivity-HiTES to Corynebacterium matruchotii, the human oral bacterium, with 3120 clinical drugs as potential elicitors. As a result, we identified two cryptic metabolites, methylindole-3-acetate (MIAA) and indole-3-acetic acid (IAA), elicited by imidafenacin, a urinary antispasmodic drug approved by the Japanese Pharmaceuticals and Medical Devices Agency (PMDA). MIAA showed weak antibacterial activity against a pulmonary disease-causing Mycobacterium conceptionense with an IC50 value of 185.7 μM. Unexpectedly, we also found that C. matruchotii metabolized fludarabine phosphate, a USFDA-approved anticancer drug, to 2-fluoroadenine which displayed moderate antibacterial activity against both Bacillus subtilis and Escherichia coli, with IC50 values of 8.9 and 20.1 μM, respectively. Finally, acelarin, a prodrug of the anticancer drug gemcitabine, was found to exhibit unreported antibacterial activity against B. subtilis with an IC50 value of 33.6 μM through the bioactivity-HiTES method as well. These results indicate that bioactivity-HiTES can also be applied to discover biotransformed products in addition to finding cryptic metabolites in microbes.

Sesquiterpenoids isolated from the rhizome of Curcuma phaeocaulis Valeton: antitumor activity, in silico molecular docking and molecular dynamics study

This work provides a deep insight into new sesquiterpenoids isolated from Curcumae Rhizoma acting as potential antitumor activity inhibitors.

Biotransformation of sesquiterpenoids: a recent insight

Sesquiterpenoids have been identified as natural compounds showing remarkable biological activities found in medicinal plants. There is great interest in developing methods to obtain sesquiterpenoids derivatives and biotransformation is one of the alternative methods for structural modification of complex sesquiterpenes structures. Biotransformation is a great drug design tool offering high selectivity and green method. The present review describes a comprehensive summary of biotransformation products of sesquiterpenoids and its structural modification utilizing a variety of biocatalysts including microorganisms, plant tissue culture and enzymes. This review covers recent literatures from 2007 until 2020 and highlights the experimental conditions for each biotransformation process.

Tautomerism and bioactivities of curcumenol, a common sesquiterpenoid widely existing in edible plants

Curcumenol was firstly revealed as a pair of hemiacetal-ketone tautomers in solutions by using temperature variation 1H-NMR experiments, 2D NMR, and chemical methods. Quantum chemical calculation allowed the explanation of its spectroscopic behavior. An antioxidative SAR study on its derivatives verified the tautomeric bio-significance. Curcumenol also remarkably enhanced myogenic differentiation and mitochondrial function.

New cryptotanshinone derivatives with anti-influenza A virus activities obtained via biotransformation by Mucor rouxii

This paper provides an efficient platform to diversify the structure and pharmaceutical potentials of known natural products. Seven metabolites were obtained via the biotransformation of cryptotanshinone by the fungus Mucor rouxii AS 3.3447, and assigned as 13R-14R-hydroxy-anhydride of 16R-cryptotanshinone (1), 1S-hydroxy-anhydride of 16R-cryptotanshinone (2), 1R-hydroxy-anhydride of 16R-cryptotanshinone (3), 3S-hydroxy-epicryptoacetalide (4), 3S-hydroxy-cryptoacetalide (5), epicryptoacetalide (6), and cryptoacetalide (7). Among these compounds, 1-5 are novel. The ortho-naphthoquinone chromophore of cryptotanshinone was degraded and rearranged by M. rouxii. 1 and 3 showed good anti-influenza A virus activities with the reduced cytotoxic activities compared to the parent substrate cryptotanshinone (8). The structures of all the new compounds were determined on the basis of HRESIMS (high-resolution electrospray ionization mass spectroscopy) spectrometry, NMR (nuclear magnetic resonance) spectroscopy, ECD (electronic circular dichroism) calculations, and the CD (circular dichroism) of "in situ" method with [Rh₂(OCOCF₃)₄].

Bioactive spirostanol saponins from the rhizome of Tupistra chinensis

Phytochemical investigations of the rhizome of Tupistra chinensis led to the isolation of six new spirostanol saponins, one new spirostanol, along with eight known spirostanols. Their chemical structures were elucidated on the basis of spectroscopic and chemical methods, including IR, NMR, MS, and GC analyses. The antiproliferative effects against five human cancer cell lines were assayed for all the isolated compounds. Compounds 8, 12 and 15 showed potent cytotoxic activities against K562 cells. The isolated compounds were evaluated for their inhibitory activities on nitric oxide (NO) production induced by lipopolysaccharide in a macrophage cell line RAW 264.7. Compounds 2 and 12 showed significant inhibition on NO production with IC50 values of 16.1±1.8 and 13.5±1.2 μM, respectively.